issue with my distributor points on my 64 Dart

I have a month old distributor that I put on my car. Drove it all day beautifully yesterday, today it would not start. I found out that the ignition point gap had changed spacing for some reason. I can wiggle the shaft that runs into my motor on the distributor back-and-forth, changing the gap size of the points. Is this normal? I know it’s supposed to be .017 and I set it to that, but it seems to run beautifully for a few minutes then seems to change again. Help!!
I'm late to the party but only have my story to tell... I was working at a tire store / auto service center years ago and my specialty was installing those car phones that had a huge transceiver under a seat, etc... Textile mill covered a bunch of Sulzer looms with plastic and laid off my wife only 2 months after she made the final loan payment on a 79 Monte Carlo. I dropped the collision coverage to save a coin or 3 (my stoopid move). She went across town to sign up for unemployment and totaled that car on her way home. Only accident that was her fault (her stoopid move).
So the 2 kids, one in a car seat, wouldn't fit in my Chevy Luv pickup LOL. I managed to toss keys with a guy who had a 67 Notchback B'cuda for sale on his front lawn. It was 225 slant. It didn't run nearly as good as the 2 vehicles we had lost but it was a square trade. After myself and the other guys in the shop did complete tune up, wires, points, everything, adjusted valves, rebuilt the carb, still the way it ran (how much the radio antenna twitched) continued to vary. Great cold, like crap hot. Fault found was a worn out distributer. Dwell all over the place. Autrozone was Auto Shack back then. When I went to pick up their reman'd distributer. I knew to check it and said, "Nope. Order me another one". Went back to pick up the second one and again, "Nope". Third time's a charm. I got a good one. That old girl ran like she had been dipped in the fountain of youth (nearly 4 years if my memory serves). There was a timing set, and a water pump, and a ballast resistor installed during that period. Then it finally poked the #5 rod through the left side of the block.. That's another story. Suffice to say if/when you do hear a bottom end knock,,, don't try to drive it to the shop (unless you are ready to the LA upgrade anyway).
Reman'd parts always have been a gamble. I recall some calling black spray paint starter renew. LOL